#include <iostream>
using namespace std;

double add(double x, double y)
{
    return x + y;
}
double add(int x, double y)
{
    return x + y;
}
double add(double x =10.1, int y = 0.1)
{
    return x + y;
}
int add(int x, int y = 10)
{
    cout << "x" << x << "y" << y << endl;
    return x + y;
}

int main()
{
    cout << add(1, 2) << endl;
    cout << add(1.3, 3.6) << endl;
    cout << add(1, 3.6) << endl;
    cout << add(1.5, 3) << endl;
    cout << add(2) << endl;
}